The intensification of the Brønsted acidic ionic liquids (BILs) with different alkyl chain lengths with or without the sulfonic acid groups on the interfacial behaviors of H2SO4/C4 hydrocarbons were studied by molecular dynamic (MD) simulation. The results indicated that the introduction of BILs into the H2SO4 can contribute to a better dissolution and diffusion of C4 hydrocarbons at the interface compared to the pure H2SO4

which is helpful to the quality of alkylate. The stronger density enrichment at interface can be found for the cations with longer alkyl chains with their alkyl chains protruding more deeply into the C4 hydrocarbons phase

which is beneficial to the enhancement of the interfacial properties. The longer alkyl chains can facilitate the dissolution of C4 hydrocarbons

but increase the survival probability at the interface and limits their interfacial diffusion. Compared to the non-SFILs

the sulfonic-acid-functionalized ILs (SFILs) can facilitate a higher dissolution of isobutane but inhibit its diffusion at the interface. In this work

the intensification on the interfacial behaviors of C4 alkylation provide deeper understanding of the C4 alkylation process. The related results are expected to help the alkylation process strengthening and optimization and design of new catalysts.